How do I set up my computer to lock when it is left unattended for a short while? (Windows)

AU Regulations and Guidelines state that staff must ensure that any computer they are using at AU is not used by unauthorised persons. ( Where can I read these? )

To lock the computer when you leave it unattended:

• Hold down the Windows key and press the L key once (NB - This is not available on public workstations)
  

To unlock the computer when you return:

• press Ctrl, Alt and Delete and enter the password used to log on to the computer

You should set your computer to lock automatically if you leave it unattended for a short while:

• From the desktop, right-mouse click and click on Personalize
• Choose Screen Saver from the window which appears
• Tick the On resume display logon screen box and choose a Wait time from the menu provided e.g. 10 minutes
• Click on Apply and then on OK to finish